Field of the Disclosure
The present disclosure relates to an oxide thin-film transistor and a method of fabricating the same.
Description of the Related Art
Flat panel displays (FPDs) are very thin and lightweight, and have a very high share in the display market. As the market share of FPDs increases, large-screen and high-definition FPDs are required. Furthermore, in order to apply FPDs to lightweight, thin, flexible and foldable displays, a backplane technology capable of processing at a low temperature and having excellent electrical and mechanical properties and ensuring operational stability is required.
A switching device or driving device used as the backplane of a display includes a silicon (Si)-based thin-film transistor (TFT) using amorphous silicon (a-Si) or polysilicon (poly-Si), and an oxide semiconductor thin-film transistor.
An amorphous silicon (a-Si) thin-film transistor, one type of silicon (Si)-based thin-film transistor, is easy to fabricate, but has low electron mobility. On the other hand, compared to an amorphous silicon (a-Si) thin-film transistor, a polysilicon (poly-Si) thin-film transistor has high electron mobility and therefore can be applied to a high-definition display with a large screen, and is excellent in terms of safety. However, in fabricating a polysilicon (poly-Si) thin-film transistor, there are problems in that the process is complicated and costly, and a compensating circuit is required due to the non-uniform characteristics of elements in a panel.
To solve these disadvantages of silicon (Si)-based thin-film transistors, oxide semiconductor thin-film transistors are being developed. Compared to conventional amorphous silicon (a-Si) thin-film transistors, oxide thin-film transistors are attracting considerable attention as driving elements for next generation displays because of high electron mobility and low leakage current thereof.
An oxide semiconductor used as the channel layer region of an oxide thin-film transistor can be broadly fabricated by two methods. First, there is a method of physically or chemically depositing an oxide semiconductor on a substrate using vacuum equipment. However, this method has a disadvantage of high production costs.
As a method for overcoming such disadvantage, there is a method of forming an oxide semiconductor using a chemical solution deposition process. However, despite an advantage of lowering production costs, an oxide thin-film transistor fabricated by a chemical solution deposition process has a disadvantage in that electrical properties are poor compared with a thin-film transistor fabricated by a vacuum process.
Therefore, there is a need to develop a method of fabricating an oxide semiconductor that is based on a chemical solution deposition process and can improve electrical properties while reducing production costs.